It is generally believed that human beings distinguish five tastes: sweetness, saltiness, sourness, bitterness and umami (savoriness), these tastes are called the five basic tastes. The taste of each food or drink is determined by a complex combination of the five basic tastes. Salt (sodium chloride) is not only a necessary component of life activity, but also a main component in producing a salty taste. Consequently, the amount of salt content in food or drink is an important factor for controlling the taste of food or drink. While, overconsumption of salt is regarded as one of the factors to cause adult disease such as high blood pressure, heart diseases and the like, therefore, reduction of salt intake is strongly expected.
The easiest and simplest method to reduce the amount of salt content in food or drink is to simply reduce the amount of salt added, or to not add salt to food or drink. However, low sodium food or drink are remarkably lacking in taste Enhancing the flavor or smell of low sodium food or drink with sour, acrid taste, citrus flavors and the like is another method to reduce the salt content, however the later method is not preferred because the original taste or flavor of the food or drink is lost.
For the above reasons, a method to reduce the salt content in food or drink has been actively developed while maintaining the original good taste of the food or drink. For example, a method to replace a part or the whole salt content with potassium salt and the like is widely used in the medical food field as a method of adding material having a salt-like taste. Other than the above example, a method of adding a seasoning composition such as gluconate, demetallic salt including the lysine, ammonium chloride, monosodium L-aspartate, L-glutamate and a nucleic acid-based material mixed in a specific ratio have been disclosed (for example, refer to patent document 1 to 3).
Other than the above method of enhancing a salt-like taste, for example, a method for enhancing a salt-like taste of food or drink that is characterized by adding γ-aminobutyric acid and an organic acid and/or the salt to the food or drink has been disclosed (for example, refer to patent document 4). In addition, a method for enhancing a salt-like taste of food or drink that is characterized by adding an acidic amino acid, a basic amino acid and a succinic acid or salt to a food containing salt has been disclosed (for example, refer to patent document 5). Other than the above method, a method for enhancing a salt-like taste of food or drink by adding fat and oil that 70% or more in all fatty acid composition is oleic acid, a method of adding acid peptide or basic amino acid, a method of adding trehalose, a method of adding a specific protein hydrolysate, a method of adding a mixture of equal moles of arginine and asparagine acid, a method of adding a specific saturated aliphatic monocarboxylic acid, a method of adding thaumatin, a method of adding a specific collagen hydrolysate and the like have been disclosed (for example, refer to patent documents 6 to 13).    [Patent Document 1] International Publication No. 96/17521    [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. Hei 06-87805    [Patent Document 3] Japanese Unexamined Patent Application, First Publication No. Hei 11-187841    [Patent Document 4] Japanese Laid-Open Patent Application No. 2004-275059    [Patent Document 5] Japanese Laid-Open Patent Application No. 2002-345430    [Patent Document 6] Japanese Laid-Open Patent Application No. 2006-262896    [Patent Document 7] International Publication No. 2001/039613    [Patent Document 8] Japanese Unexamined Patent Application, First Publication No. Hei 10-66540    [Patent Document 9] Japanese Unexamined Patent Application, First Publication No. Hei 7-289197    [Patent Document 10] U.S. Pat. No. 5,145,707    [Patent Document 11] Japanese Unexamined Patent Application, First Publication No. Hei 05-184326    [Patent Document 12] Japanese Unexamined Patent Application, First Publication No. Sho 63-137658    [Patent Document 13] Japanese Unexamined Patent Application, First Publication No Sho 63-3766